Soccernet's Insider reports:
'Here 'cos it's Wigan, you're only here 'cos it's Wigan.' Perhaps the home crowd were flattering themselves, but who could blame them? As Wigan completed their 27-year journey from non-league to Premier League, there was, understandably, something of a festival feel around the JJB Stadium.
As your correspondent arrived, the Latics All Stars (cheerleaders, not Mick Quinn, Mike Newell and other distinguished old boys) got their pom-poms out to dance. From a stall came the sound of the J.Geils Band 'classic' Centerfold blaring out.
Inside the ground, the entertainment continued, though bringing in opera singer Lawrence Robinson on to the pitch may have backfired. The Chelsea supporters launched into an enthusiastic rendition of 'Jose Mourinho'.
But the PR offensive carried on. The match programme came with one booklet titled 'Wigan: A Premier Town' and another, '25 things you never knew about Wigan'. And it came as news to this observer that Angus Fraser, the permanently red-faced England cricketer who began every spell with the air of a man who had just completed a marathon, was born in Wigan.
Anyway, this was civic pride in excelsis. In this context, comparisons with Barnsley are obvious, but as a club, Wigan have more in common with Bolton, with just a hint of Blackburn, Charlton and Ipswich about them; resources, facilities and the nous to suggest survival is no pipe dream.
But, the last time your correspondent watched Wigan, they drew 1-1 with Accrington Stanley. It was hard to say who was the better team.
And without a hint of flattery, Jose Mourinho was able to deliver a similar verdict here. He had a point; Wigan more than bridged the divide from Accrington to Chelsea.
But they could be forgiven for approaching Henri Camara with a sense of trepidation. The Senegalese has speed and skill, and an unfortunate habit of getting relegated. It all suggests a deluxe, 21st century version of Nathan Blake. But twice within five minutes, he had the sharpness and quick footwork to elude the Chelsea defence. Petr Cech saved his first shot, while the second fizzed into the side-netting.
Then, a show of fearlessness from Jimmy Bullard. He accelerated away from Arjen Robben - who made a despairing attempt to bring him down - used his skill to escape Claude Makelele's attentions and then laid the ball off to a team-mate before being clattered by Eidur Gudjohnsen.
Next up, a glaring miss from Alan Mahon, blazing over from eight yards after Camara dispossessed Frank Lampard. That, in itself, is something of a rarity, but an indication of an unusually sluggish Chelsea performance.
Ah yes, Chelsea. They've had another quiet summer: Premier League inquiries, more record fines, ongoing transfer sagas, £29 million spent (a sum that could yet be doubled), and Mourinho watched 'Fantastic Four' (twice).
The nifty quartet he picked today were Robben, Lampard, Gudjohnsen and Damien Duff, roaming between Claude Makelele and Didier Drogba, it was as much 4-1-4-1 as 4-3-3 But a double substitution at half-time was either a rare show of dissatisfaction or an indication of the options at his disposal. Mourinho swiftly confirmed it was the former. And it took the introduction of Shaun Wright-Phillips and then, on the hour, Hernan Crespo, to bring some urgency.
To counter Chelsea's attacking arsenal, Wigan's game plan was simple, but effective: defend deep. It's fair to say pace does not rank near the top of any list of Arjan de Zeuuw and Stephane Henchoz's strengths, but they defended immaculately; judgment and timing are underrated merits for centre backs to possess.
Alongside them, right back Pascal Chimbonda had a hugely successful debut, seeing off first Robben and then Duff. Mourinho gave him a third opponent on the left flank, shifting Asier del Horno forward and switching to 3-5-2.
It was almost the catalyst for a Wigan winner. Twice Gary Teale was granted more room on Wigan's right flank; Damien Francis headed his first cross on to the bar and Andreas Johansson volleyed the second over.
And deep into injury time, the cruellest of twists to the tale, courtesy of Crespo, with a truly wonderful winner to end a strangely poor Chelsea performance. It was, as Mourinho admitted, undeserved.
The last time Wigan beat Chelsea, the Daily Mirror's alliterative headline was 'Ferret Fancier Fells Fashionable Chelsea'. Sadly, we will not find out if Paul Jewell's team share the same proclivities as their predecessors. But they could have felled fashionable Chelsea.